VDOT criteria for placement of Sharrows and Bicycles May Use Full Lane signs

In an earlier post we noted that Shared Lane Markings (Sharrows) and Bicycles May Use Full Lane (BMUFL) signs are appearing in Fairfax. We discussed one narrow, busy section of Idylwood Road where cyclist harassment is frequent. We pondered whether using sharrows and the BMUFL signs could be used on some sections of road. We posed our question to Randy Dittberner, VDOT Traffic Engineer. We received a very informative response and wanted to pass it on:

As we were developing our initial list of sites to consider for implementation, we focused on a few factors:

- BMUFL signs and sharrows provide similar guidance to drivers, with a few distinctions. For example, we believe that sharrows may be preferred adjacent to parked cars to better advise cyclists to stay out of the door zone.

- Both devices cost about the same to install, but they have different life expectancy. Signs will last for at least a decade, but sharrows will be constantly pummeled by traffic since they’re often directly in vehicles’ wheel paths. As such, we are concerned that sharrows may need to be refreshed frequently, which obligates us to ongoing maintenance. We are closely monitoring the sharrows on Westmoreland to see how they hold up under traffic.

- It is our initial hope that in most cases, we can achieve a significant benefit with either the sign or the marking, without installing both. This strategy will allow us to address (at least) twice as many sites for the same cost. Certainly there may be critical sites where both devices are needed and add value, and we will definitely consider doing so.

With this in mind, we elected to focus our initial deployment of sharrows on locations where there is a gap in or terminus of an existing marked bike lane. In these areas we have already made a commitment to maintaining pavement marking expressly aimed at cyclists, and the sharrow acts to extend the markings through the gap or beyond the terminus. We focused our initial deployment of BMUFL signs on locations without marked bike lanes.